Chair having tilting seat and back

ABSTRACT

An ergonomic chair includes a support body having a seat support portion and a back support portion. A forward sloping seat track is positioned on the seat support portion. A first seat portion engages the seat track on the seat support portion for forward and rearward movement along the seat track between a forward position and a rearward position. A second seat portion is provided having an upwardly extending back rest. The second seat portion is pivotally connected to the first seat portion. Movement of the first seat portion forward along the seat track toward the forward position draws the second seat portion forward with forward movement of the second seat portion causing movement of the back rest downwardly. This allows for subtle movement forward and backward movement that energizes major leg muscles.

FIELD

There is described a chair with a seat and back that tilt to provide ergonomic seat positions.

BACKGROUND

U.S. Pat. No. 8,272,692 (Epperson) entitled “Office Chair Having Tiltable Seat And Back”, describes a chair with a seat and back that tilt to provide ergonomic seat positions. There will now be described a chair that is an alternative to Epperson and is believed to provide advantages over Epperson.

SUMMARY

There is provided a chair which includes a support body having a seat support portion and a back support portion. A seat track is positioned on the seat support portion. A first seat portion engages the seat track on the seat support portion for forward and rearward movement along the seat track between a forward position and a rearward position. A second seat portion is provided having an upwardly extending back rest. At least one back rest track is provided on one of the back support portion or the back rest. At least one track follower is provide on another of the back support portion or the back rest. The second seat portion is pivotally connected to the first seat portion. Movement of the first seat portion forward along the seat track toward the forward position draws the second seat portion forward with forward movement of the second seat portion causing movement of the back rest downwardly with such movement accommodated by cooperation of the at least one back rest track and the at least one track follower.

The chair, as described above, allows for subtle forward and backward movement. This movement activates the major muscle groups in the legs without being distracting or interfering with work activities.

Although beneficial results may be obtained through the use of the chair, as described above, it has been found that more beneficial results may be obtained when the first seat portion is biased into the rearward position. With biasing, after the user has consciously exerted a force to move the first seat portion forward, the first seat portion is drawn slowly back to the starting position as the force is released.

Although beneficial results may be obtained through the use of the chair, as described above, it has been determined that a seat track which is arcuate and symmetrical works the best. When the first seat portion moves forward, the second seat portion is drawn forwardly and upwardly. This serves a number of purposes. It serves to bias the first seat portion and the second seat portion to the rearward position, it accentuates the movement and it helps the user avoid sliding forward.

In order to improve aesthetic appearance, it is preferred that the first seat portion and the second seat portion share an overlying fabric covering. In order to improve comfort and help the user avoid sliding forward, all or a portion of the overlying fabric covering the second seat portion may be provided with a friction inducing and pressure relieving profile.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:

FIG. 1 is a side elevation view of a chair having tilting seat and back in a rearward position.

FIG. 2 is a side elevation view of the chair of FIG. 1 in a forward position.

FIG. 3 is a detailed side elevation view of the seat track when the chair is in a rearward position, as shown in FIG. 1.

FIG. 4 is a detailed side elevation view of the seat track when the chair is in a forward position, as shown in FIG. 2.

FIG. 5 is a detailed side elevation view of the back rest track when the chair is in a rearward position, as shown in FIG. 1.

FIG. 6 is a detailed side elevation view of the back rest track when the chair is in a forward position, as shown in FIG. 2.

FIG. 7 is a top plan view of the chair of FIG. 1.

DETAILED DESCRIPTION

A chair, generally identified by reference numeral 10, will now be described with reference to FIG. 1 through FIG. 7.

Structure and Relationship of Parts:

Referring to FIG. 1 and FIG. 2, chair 10 consists of a support body 12 having a seat support portion 14 and a back support portion 16. A seat track 18 is positioned on seat support portion 14. A first seat portion 20 engages seat track 18 on seat support portion 14 for forward and rearward movement along arcuate seat track 18 between a forward position, as shown in FIG. 2 and a rearward position, as shown in FIG. 1. Movement of first seat portion 20 along seat track 18 is facilitated by ball bearings 22. It will be apparent that movement could be accommodated without the use of ball bearings or with other types of engagement. It is preferred that seat track 18 defines a symmetrical arcuate path. FIG. 3 illustrates first seat portion 20 in a rearward portion on seat track 18. FIG. 4 illustrates first seat portion 20 on a forward position on seat track 18.

Referring to FIG. 1 and FIG. 2, a second seat portion 24 is provided having an upwardly extending back rest 26. Referring to FIG. 7, first seat portion 20 and second seat portion 24 share an overlying fabric covering 28. That portion of overlying fabric covering 28 that covers second seat portion 24, preferably has a friction inducing and pressure relieving profile in the form of openings 30.

Two back rest tracks 32 are provided, one on each side of back rest 26. A pair of track followers 34 are provided on back support portion 16. Track followers 34 move along back rest tracks 32 during relative movement of back rest 26 and back support portion 16. It will be appreciated that this could be reversed with track followers 34 positioned on back rest 26 and back rest tracks 32 on back support portion 16.

Referring to FIG. 1 and FIG. 2, second seat portion 24 is pivotally connected by a hinge connection 36 to first seat portion 20. In view of hinge connection 36, when pressure is exerted to move first seat portion 20 forward along seat track 18 toward the forward position, second seat portion 24 is drawn forward with forward movement of first seat portion 20. Referring to FIG. 5, back rest 26 is shown in the rearward position. Referring to FIG. 6, as second seat portion 24 drawn forward, back rest 26 is drawn downwardly with such movement being accommodated by back rest tracks 32 and track followers 34.

Referring to FIG. 1 and FIG. 2, first seat portion 20 is biased by a spring 38 to the rearward position. First seat portion 20 will always return to the rearward position when pressure is removed. It will be apparent that biasing can be accomplished by other means, such as a slope to induce a gravity return or a bungee cord.

Referring to FIG. 1 and FIG. 2, support body 12 is illustrated has having a flat base 40 and a single vertical support column 42. It will be appreciated that base 40 may be of various shapes, such as a spider or multi-legged shape and may also have casters at the ends for rolling chair 10.

Operation:

Referring to FIG. 1, a user sits centered with his or her tailbone positioned on second seat portion 24 with the user's back flush against back rest 26, in the default rearward position of chair 10. As the user exerts a forward and downward pressure through their thighs onto first seat portion 20, first seat portion 20 slides forward and downward along the arcuate seat track 18. As first seat portion 20 slides forward, second seat portion 24 is drawn forward and slightly upward arcuate seat track 18 because hinge connection 36 ties movement of second seat portion 24 to movement of first seat portion 20.

With the forward movement of second seat portion 24, an upper portion of back rest 26 is drawn downwards with movement of back rest 26 being accommodated by back rest tracks 32 and track followers 34. Referring to FIG. 2, this results in first seat portion 20 being in a forward and downward sloping position and back rest 26 being in a reclined position. As the user lessens or removes the forward and downward pressure exerted on first seat portion 20, spring 38 pulls first seat portion 20 rearwards and upwards along arcuate seat track 18. As first seat portion 20 moves rearward on arcuate seat track 18, second seat portion 24 is pushed rearward by the movement of first seat portion 20. As the second seat portion 24 moves rearward, movement of back rest 26 is accommodated by back rest tracks 32 and track followers 34. This returns chair 10 to the default rearward position of FIG. 1.

Advantages:

1. The movement of the above described chair is subtle and can be effected without interfering with the work activities of a person seated behind a desk.

2. The movement activates the major muscle groups in the legs and, as such, plays a role in maintaining fitness and burning calories.

3. With their tailbone positioned on second seat portion 26, users do not slide off the seat as they tilt the seat forward and move into a reclined position. In contrast, when a unitary seat is inclined it is difficult to avoid sliding forward.

4. The slight upward tilt of the second seat portion 26, combined with the downward tilt of first seat portion 24, opens up the hip-thigh angle, which helps to restore the natural lordosis (inward curve) of the lumbar spine. This results in increased comfort for the user and decreased time spent sitting in a slumped (kyphotic) sitting posture, which has been shown to be a major source of lower back pain for office workers.

In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

The scope of the claims should not be limited by the illustrated embodiments set forth as examples, but should be given the broadest interpretation consistent with a purposive construction of the claims in view of the description as a whole. 

What is claimed is:
 1. A chair, comprising: a support body having a seat support portion and a back support portion; a seat track on the seat support portion; a first seat portion engaging the seat track on the seat support portion for forward and rearward movement along the seat track between a forward position and a rearward position; a second seat portion engaging the seat track on the seat support portion for forward and rearward movement along the seat track, the second seat portion having an angularly fixed upwardly extending back rest; at least one back rest track on one of the back support portion or a remote end of the back rest, and at least one track follower on another of the back support portion or the remote end of the back rest; the second seat portion being pivotally connected to the first seat portion, such that movement of the first seat portion forward along the seat track toward the forward position draws the second seat portion forward with forward movement of the second seat portion causing movement of the back rest downwardly with such movement accommodated by cooperation of the at least one back rest track and the at least one track follower.
 2. The chair of claim 1, wherein the first seat portion is biased into the rearward position.
 3. The chair of claim 1, wherein the back rest track is linear.
 4. The chair of claim 1, wherein the seat track is arcuate.
 5. The chair of claim 1, wherein the first seat portion and the second seat portion share an overlying fabric covering.
 6. The chair of claim 5, wherein a portion of the overlying fabric covering the second seat portion having a friction inducing and pressure relieving profile.
 7. A chair, comprising: a support body having a seat support portion and a back support portion; a forward sloping arcuate seat track on the seat support portion; a first seat portion engaging the arcuate seat track on the seat support portion for forward and rearward movement along the arcuate seat track between a forward position and a rearward position; a second seat portion engaging the arcuate seat track on the seat support portion for forward and rearward movement along the arcuate seat track, the second seat portion having an angularly fixed upwardly extending back rest; the first seat portion and the second seat portion share an overlying fabric covering, a portion of the overlying fabric covering the second seat portion having a friction inducing and pressure relieving profile; two linear back rest tracks on one of the back support portion or a remote upper end of the back rest, and a pair of track followers on another of the back support portion or the remote upper end of the back rest; the second seat portion being pivotally connected to the first seat portion, such that when pressure is exerted to move first seat portion forward along the arcuate seat track toward the forward position the second seat portion is drawn forward with forward movement of the second seat portion causing movement of the back rest downwardly along the back rest track; and the first seat portion being biased to the rearward position, such that the first seat portion returns to the rearward position when pressure is removed. 